Recently, as global interest in an environmentally-friendly and high-efficiency vehicle increases, research and development for a vehicle using a next-generation energy source have been conducted as an essential project. For example, a fuel cell using hydrogen gas as energy source has received great attention as a non-polluting vehicle.
In current vehicle industry, various types of fuel cells have been developed. However, since such fuel cells for a vehicle may be required to have high efficiency, output concentration, short starting time, rapid response characteristics depending on a change in load, and the like, study has been focused on commercialization of a fuel cell vehicle where a polymer electrolyte member fuel cell may be applied.
In the fuel cell, hydrogen reacts with oxygen in the air to generate electric energy and generate water as a by-product. Further, in the fuel cell, the water needs to be discharged to a channel from a cathode catalyst layer via a gas diffusion layer (GDL) and the oxygen needs to be sufficiently supplied from the channel to the catalyst layer via the gas diffusion layer. In addition, the fuel cell should be operated at an optimal temperature of about 60° C. to 80° C.
When the temperature is less than the optimal temperature, the water may be condensed inside the catalyst layer and the gas diffusion layer or the water may be condensed or flooded in the channel and thus block the supplied oxygen, thereby reducing the performance of the fuel cell. When the temperature is greater than the optimal temperature, the water inside the membrane may dry up, thereby reducing the performance of the fuel cell.
As such, it is critical to maintain the optimal temperature of fuel cell operation.
The fuel cell vehicle may require greater time to be preheated when a vehicle starts at room temperature. When the fuel cell vehicle is rapidly accelerated without sufficient preheating, a large amount of water may be generated. As consequence, the water may be condensed inside the catalyst layer and the gas diffusion layer or the water may be condensed or flooded in the channel, which may cause blocking the oxygen supplied to the catalyst in a cathode of the fuel cell.
Therefore, the fuel cell vehicle in the related art may limit output of the fuel cell before the fuel cell is sufficiently preheated to control an appropriate amount of water to be discharged through the channel. However, the condensed water may not be easily discharged to the outside.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.